1. Field of the Invention
The present utility model is related to a backlight module, and more particularly, to a backlight module that does not reserve additional spaces as its light mixing distance.
2. Description of the Prior Art
Liquid crystal display devices have advantages such as low radiation, thin profile, and low power consumption. They are widely applied in personal digital assistants (PDA), notebook computers, digital cameras, mobile phones, as well as in many other consumer electronics. Since a liquid crystal display panel is not self-luminous, a backlight module disposed at a bottom of the liquid crystal display panel is necessary for supplying a light source to the liquid crystal display panel which displays images.
Conventional backlight modules often use cold cathode fluorescent lamps (CCFL) as light sources; however, CCFL contains mercury (Hg) and other harmful substances which are difficult to recycle as well as not environmental friendly. Consumers nowadays are more aware of environment issues, driving the demand for environmental friendly electronics. With a strong demand in recyclable electronics, the mercury-containing CCFL will be gradually replaced.
In addition, prior art backlight modules are classified into an edge type or a direct type depending on the position of a light source. However, both the edge type and the direct type backlight modules require a light mixing distance to accomplish even brightness and color effects. In order to satisfy a minimum required light mixing distance, either widths of the backlight module's edges or thicknesses of the backlight modules have to be increased. As a result, volumes of the backlight modules are also increased which goes against the demand for backlight modules with thinner profiles.